• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.1
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• pp.1-8
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• 2011

Introduction: The utility of the C-terminal cross-linking telopeptide test (CTX) as a method for staging Bisphosphonate-related osteonecrosis of the jaws (BRONJ) and its healing process was examined. Materials and Methods: A total 19 patients who were diagnosed with BRONJ underwent a fasted morning CTX test, were enrolled in this study. The serum CTX values ranged from 50 to 630 pg/mL (mean 60). The risk assessment was rated according to the CTX values of the individual patient (minimal risk, ${\geq}$ 150 pg/mL, moderate, 100 to 150 pg/mL, high, ${\leq}$100 pg/mL). The BRONJ scores were then calculated according to the number of BRONJ lesions and their stage. The operation was done as soon as possible, regardless of BORNJ stage. Results: The mean duration of bisphosphonate therapy was 4.1 years. Of the 19 patients, 15, 2 ans 2 received alendronate, risedronate and zoledronate, respecively. Of the 19 patients who underwent a sequestrectomy, saucerization and smoothing, 15 healed after the initial surgery, 1 patient healed after one more surgical procedure, 3 patients did not heal completely but showed improvement in symptoms. Therefore, 17 out of the 19 patients healed completely with complete mucosal coverage and the elimination of pain. The risk assessment using the CTX value and disease severity were not correlated (r=-0.264, P=0.275). In addition, the risk assessment using CTX value and healing after surgery were not correlated (r=-0.147, P=0.547). Conclusion: The serum CTX should be considered carefully by clinicians as part of overall management. Early surgical intervention is of benefit in the treatment of stage II BRONJ.

• Journal of Intelligence and Information Systems
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• v.11 no.3
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• pp.83-101
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• 2005

Customer retention is one of the major issues in life insurance industry, in which competition is increasingly fierce. There are many things for the life insurers to do many things to retain the customers. One of those things is to make sure to keep in touch with all customers. When an insurance-planner resigned, his/her customers must be taken care of by some planner-assistants. This article outlines the design of Contact Scheduling System (CSS) that supports planner-assistants for contacting the customers. Planner-assistants are unable to share the resigned insurance-planner's experience and knowledge regarding the customer relationship management. The CSS developed by employing both Classification And Regression Tree (CART) technique and Sequential Pattern Mining (SPM) technique has a two-stage process. In the first stage, it segments the customers into eight groups by CART model. Then it generates contact scheduling information consisting of contact-purpose, contact-interval and contact-channel, according to the segment's typical contact pattern. Contact-purpose is derived by schedule-driven, event-driven, or business-rule-driven. Schedule-driven contact is determined by SPM model. In the operation of CSS in a realistic situation, it shows a practicality in supporting planner-assistants to keep in touch with the customers efficiently and effectively.

• Advances in pediatric surgery
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• v.16 no.2
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• pp.134-142
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• 2010

Malignant ovarian tumors in children are very rare, and consist of about 1 % of all childhood malignant tumors. The purpose of this study is to examine the clinical characteristics, treatment, and prognosis for children with malignant ovarian tumors. We retrospectively reviewed the medical records of children under 15 years of age with malignant ovarian tumors who had been treated surgically at Asan Medical Center between 1989 and March 2009. There were 32 patients, ranged in age at surgery from 2 to 15 years (mean; 10.4 years). The median follow-up period was 64.7 months (from 1 month to 188 months). Pathologic diagnosis were; immature teratoma (n=10), mixed germ cell tumor (n=10), and dysgerminoma (n=6). Tumor stage was classified by the staging system of the International Federation of Gynecology and Obstetrics (FIGO). The number of patients in stage I, II, III, and IV were 24 (75 %), 2 (6.2 %), 4 (12.5 %), and 2 (6.1 %), respectively. The tumor recurred in 4 patients. Seven patients of group 1 did not receive postoperative adjuvant chemotherapy, and in three of them, the tumor recurred. Twenty-five patients (group 2) underwent postoperative adjuvant chemotherapy, and there was only one recurrence. One patient who did not receive postoperative adjuvant chemotherapy and expired 10 months after operation because of tumor recurrence and distant metastasis. The overall 5-year event free survival (EFS) was 84.2 %: group 1 in 44.4 %, and group 2 in 95.7 %. Tumor recurrence was related to the postoperative adjuvant chemotherapy (p=0.004). In conclusion, proper surgical procedures with relevant postoperative adjuvant chemotherapy might improve clinical results in children with malignant ovarian tumors.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.285-291
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• 1991

One hundred and twenty six patients with early uterine cervical cancer who had been treated at Departmen of Radiation Oncology of Korea University Hospital from Jan.1981 to Dec.1988 were analysed retrospectively by the treatment result and pattern of of failures. All patients had stage Ia to IIa disease and were grouped whether they had combination of operation and postop irradiation or radiation therapy alone. 1) Sixty six patients belonged to the combination treatment group and 60 patients to the radiation alone group. 2) Combination group consisted of $18.1\%$(12/66) stage Ia, $71.2\%$(47/66) stage Ib and $10.6\%$ (7/66) stage IIa patients. There were no stage Ia, 18.8$\%$(l1/60) stage Ib and 81.6$\%$(49/60) stage IIa patients for RT alone gronp. 3) There were total 23$\%$(29/126) treatment failures,13 patients in combination group and 16 patients in RT alone group. In 66 patients of combination group, they were found to have 5 locoregional failures, 7 distant failures and 1 at both sites. In 60 patients of RT alone group, 9 locoreginal failure and 7 distant failures occured. Eighty six percent (25/29) of total failures appeared within 18 month after completion of treatment. About 60$\%$ of the patients with regional recurrences which were located at pelvic side wall or pelvic lymph nodes paesented their recurrent disease after 1 year of completion of treatment, whereas same percent of distant failures appeared within 6 month. 5) In RT alone group, the first sites of distant failure were mostly para-aortic lymph node and/or left supraclavicular lymph node (71.4$\%$,5/7). In combination group, various sites such as inguinal lymph node, mediastinal lymph node, liver, lung and bone appeared first or at the same time with para-aortic and supraclavicular lymph node metastasis. 6) Logistic regression analysis was done for multivariate analysis of the factors contributing to locoregional and distant failures. In combination group, adequacy of the resection margin and the presence of positive pelvic node were found to be the most significant factors (p=0.0423 & 0.0060 respectively). In RT alone group, less than complete regression of the tumor at the end of treatment was the only significant contributing factor for the treatment failures (p=0.0013) with good liklihood ratio.

• Radiation Oncology Journal
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• v.29 no.1
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• pp.11-19
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• 2011

Purpose: To evaluate the pathological and clinical effects of preoperative chemoradiation (CCRT) in cases of locally advanced rectal cancer and to determine the predictive factors for tumor downstaging. Materials and Methods: From March 2004 to August 2008, 33 patients with locally advanced rectal cancer were treated with preoperative CCRT. Twenty-eight patients (84.8%) were treated using a concomitant boost technique while five (15.2%) patients were treated using a cone down boost technique. All patients received 50.4 Gy of irradiation and concurrent chemotherapy with 5-fluorouracil. The median follow-up duration was 24.2 months (range, 9.8 to 64.7 months). Results: Thirty-one (93.9%) patients underwent surgery. Twenty-four patients (72.7%) underwent anal sphincter-preserving surgery. The 3-year disease free survival (DFS) and overall survival rates were 63.4% and 78.8%, respectively. Post-operative factors were more important for DFS. Pathologic N stage, margin status, and pathologic differentiation were significant prognostic factors (p=0.001, 0.029, 0.030). Tumor size and lymphovascular invasion were also associated with marginal significance (p=0.081, 0.073). However, only pre-treatment T stage was a significant pre-operative factor (p=0.018). The complete pathological response rate was 9.1 %. T-downstaging was observed in ten (30.3%) patients, whereas N-downstaging was found in 24 (72.7%) patients. Pre-treatment T stage and the interval between CCRT and operation were the predictive factors for downstaging in a univariate analysis (p=0.029, 0.027). Pre-treatment carcinoembryogenic antigen was also associated with marginal significance (p=0.068). Conclusion: The survival of rectal cancer patients can be better determined based on post-operative findings. Therefore, pre-operative CCRT for downstaging of the tumor seems to be important. Pre-treatment T stage and the interval between CCRT and operation can be used to predict downstaging.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.12-28
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• 2021

Based on the global smart city promotion trend, in 2018, the "Fourth Industrial Revolution Committee" selected "sustainability" and "people-centered" as keywords in relation to the direction of domestic smart city policy. Accordingly, the Living Lab program, which is an active citizen-centered innovation methodology, is applied to each stage of the domestic smart city construction project. Through the Living Lab program, and in collaboration with the public and experts, the smart city discovers local issues as it focuses on citizens, devises solutions to sustainable urban problems, and formulates a regional development plan that reflects the needs of citizens. However, compared to citizen participation in urban regeneration projects that have been operated for a relatively long time, participation in smart city projects was found to significantly differ in level and sustainability. Therefore, this study conducted a comparative analysis of the characteristics of citizen participation at each stage of an urban regeneration project and, based on Arnstein's "Participation Ladder" model, examined the level of citizen participation activities in the Living Lab program carried out in a smart city commercial area from 2018 to 2019. The results indicated that citizen participation activities in the Living Lab conducted in the smart city project had a great influence on selecting smart city services, which fit the needs of local residents, and on determining the technological level of services appropriate to the region based on a relatively high level of authority, such as selection of smart city services or composition of solutions. However, most of the citizen participation activities were halted after the project's completion due to the one-off recruitment of citizen participation groups for the smart city construction project only. On the other hand, citizens' participation activities in the field of urban regeneration were focused on local communities, and continuous operation and management measures were being drawn from the project planning stage to the operation stage after the project was completed. This study presented a plan to revitalize citizen participation for the realization of a more sustainable smart city through a comparison of the characteristics and an examination of the level of citizen participation in such urban regeneration and smart city projects.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.223-230
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• 2003

The purpose of this study was to evaluate the effects of HACCP implementation. The HACCP education was provided twice within one month to 20 employees of a contracted food service operation in Daegu. Critical control points (CCP) were determined based on food preparation processes: non-heating, preparation after heating, and heating. We evaluated the effects of HACCP implementation by checking microbiological quality, time and temperature at each of the CCPs during the receiving, preparation, cooking, and serving stages. After HACCP implementation, the biggest changes in microbiological qualities were in heated foods. At the cooking and serving stages, the microbiological qualities of heated foods improved to the standard levels. HACCP education helped employees ensure that the internal temperatures of the heated foods were kept higher than the standard (74 $^{\circ}C$) and the food holding temperature avoided the dangerous zone (5-6$0^{\circ}C$), thus lowering microbiological levels. At the serving stage, the microbiological levels of utensils also improved after HACCP education. This result strongly suggests that it is essential to educate employees in managing the temperature to treat foods safely. However, HACCP education didn't affect the microbiological levels of non-heated foods and foods prepared after heating, which continued to be higher than the standard. The reason for this was that poor microbiological quality seasonings were added to those types of foods. This indicates that seasoning factories as well as food service operations should implement HACCP to reduce hazards.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.2
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• pp.227-232
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• 2016

To test the effectiveness of using an energy storage system for frequency regulation, the Energy New Business Laboratory at KEPCO Research Institute installed a 4 MW energy storage system (ESS) demonstration facility at the Jocheon Substation on Jeju Island. And after the successful completion of demonstration operations, a total of 52 MW ESS for frequency regulation was installed in Seo-Anseong (28 MW, governor-free control) and in Shin-Yongin (24 MW, automatic generation control). The control system used in these two sites was based on the control system developed for the 4 MW ESS demonstration facility. KEPCO recently finished the construction of 184 MW ESS for frequency regulation in 8 locations, (e.g. Shin-Gimjae substation, Shin-Gaeryong substation, etc.) and they are currently being tested for automatic operation. KEPCO plans to construct additional ESS facilities (up to a total of about 500 MW for frequency regulation by 2017), thus, various operational tests would first have to be conducted. The high-speed characteristic of ESS can negatively impact the power system in case the 500 MW ESS is not properly operated. At this stage we need to verify how effectively the 500 MW ESS can regulate frequency. In this paper, the effect of using ESS for frequency regulation on the power system of Korea was studied. Simulations were conducted to determine the effect of using a 524 MW ESS for frequency regulation. Models of the power grid and the ESS were developed to verify the performance of the operation system and its control system. When a high capacity power plant is tripped, a 24 MW ESS supplies power automatically and 4 units of 125MW ESS supply power manually. This study only focuses on transient state analysis. It was verified that 500 MW ESS can regulate system frequency faster and more effectively than conventional power plants. Also, it was verified that time-delayed high speed operations of multiple ESS facilities do not negatively impact power system operations. It is recommended that further testing be conducted for a fleet of multiple ESSs with different capacities distributed over multiple substations (e.g. 16, 24, 28, and 48 MW ESS distributed across 20 substations) because each ESS measures frequency individually. The operation of one ESS facility will differ from the other ESSs within the fleet, and may negatively impact the performance of the others. The following are also recommended: (a) studies wherein all ESSs should be operated in automatic mode; (b) studies on the improvement of individual ESS control; and (c) studies on the reapportionment of all ESS energies within the fleet.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.35-45
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• 1996

After transplantation of groin free flap was sucessed by the Daniel and Taylor in 1973, the reconstruction of plastic surgery was extensive and universal due to rapidly developement of anatomic study of the donor site and technique of microvascular surgery. The free tissue transfers is possible to be early activity and rehabilitation by one stage operation. It currently available allow transfer of specific tissue quality as bone, muscle, nerve to achieve a functional and cosmetic result as well as the most favorable secondary defect. But free flaps require critical, skillful technique and lengthy operating time. Also it has disadvantage of donor site morbity at the large tissue transfer. Authors were transferred with 107 cases in 103 patients from May 1987 to June 1996, and then we analysed free tissue transfer to acquire more increased sucess rate, satisfactory functional and cosmetic results. The sexual distribution was male prominent in 79 cases(76.7%), female in 24(23.3%) and age was variable distribution from 3 to 76 years old. The cause of defects was most prevalent in trauma of traffic and industrial accident in 51 cases(49%). The common recipient site were lower extremities in 47 cases(43.9%), upper extremities in 28 cases(26.5%), head and neck in 25 cases(23.4%), and trunk in 7 cases(6.5%). The type of transfer were free skin flaps in 46 cases(43%), free muscle or musculocutaneous flaps in 31 cases(29%), free vasculized or osteocutaneous flaps in 10 cases(9.3%), and specilized free flaps in 20 cases(18.7%). The anastomosis of artery was end to end anastomosis in 94 cases(87.9%), end to side anastomosis in 13 cases(12.1%) and all vein was end to end anastomosis. The number of anastomosed vessels were one artery one vein in 62 cases(57.9%), one artery two vein in 45 cases(42.1%) and vein graft was performed only one case. The postoperative mornitoring were used with temperature, color of flap, capillary refilling time, ultrasonogram, bone scan, doppler, and endoscopy. The reexploration was performed in 9 cases(8.4%), and then flap was loss in 3 cases(2.8%). Accordingly overall success rate was 97.2%. The postoperative complication was early vascular occlusion, hematoma, partial necrosis and late bulkiness, scarring, color dismatch etc. Therefore, free tissue transfer is the preferred method of treatment, even through conventional local and distant flaps are available.